The embodiments described herein relate generally to an electric machine, and more specifically, to an electric machine which includes features for providing fluid cooling of the machine.
An electric machine is typically in the form of an electric generator or an electric motor. The machine typically has a centrally located shaft that rotates relative to the machine. Electrical energy applied to coils within the motor initiates this relative motion which transfers the power to the shaft and, alternatively, mechanical energy from the relative motion of the generator excites electrical energy into the coils. For expediency the machine will be described hereinafter as a motor. It should be appreciated that a motor may operate as a generator and vice versa.
A stationary assembly, also referred to as a stator, includes a stator core and coils or windings positioned around portions of the stator core. It is these coils to which energy is applied to initiate this relative motion which transfers the power to the shaft. These coils are formed by winding wire, typically copper, aluminum or a combination thereof, about a central core to form the winding or coil. An electric current is directed through the coils which induces a magnetic field. It is the magnetic field that initiates this relative motion which transfers the power to the shaft.
No matter how efficient the motor, the electrical current generates heat. Removing heat from the interior of the motor is desirable for the durability and efficiency of the motor. Motors may have features to facilitate heat transfer away from the motor which in effect facilitates cooling of the motor. Such features fail to provide sufficient fluid flow for effective heat transfer, particularly for large motors and for motors with lower efficiencies.
The present invention is directed to alleviate at least some of these problems with the prior art.